Electrical apparatus



July 1, 1930.

| s. KEILHOLTZ 1,768,607

ELECTRICAL APPARATUS Filed Nov; 10, 1926 Patented July I, 1930 UNITED STATES PATENT OFFIC LESTER S. KEILHOLTZ, OF DAYTON, OHIO, ASSIGNOR TO DELCO-LIGHT COMPANY, OF DAYTON, OHIO, A CORPORATION OF OHIO ELECTRICAL APPARATUS Application filed November 10, 1926.

The present invention relates to electrical systems of control, and particularly to systems in which there is provided a plurality of work circuits energized by a limited source of supply; such as a house lighting plant, which source of supply is sufficient for one of said circuits but insufficient for supplying current to two work circuits simultaneously.

One of the objects of the present invention is to provide a system of control in which one work circuit is rendered inoperative when another work circuit is rendered operative.

In certain types of devices which are energized by a limited source of supply, it is desirable that the current for this device be available as soon as there is a demand for current by the device, although another device is receiving current from the source of supply, and although the combined demand is in excess of the current available. Another object of the present invention is to provide a system of control whereby the demand of one of the devices is subordinate to the demand for current by another device so that the superior demand is satisfied and the current supply for the subordinate device is temporarily delayed.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

The figure of the drawing is a diagrammatic view showing a refrigerating system and a water system supplied with current from a generating plant.

Referring to the drawing, there is shown a pump power head 20 which is driven by a motor 21. Current for the motor is sup plied by conductor wires 22 and 23. The power head 20 actuates a pump contained within a well casing 2i and causes water to flow from the well into a pressure storage tank 25 through pipe 26, check valve 27 and a pipe 28. A pressure-operated snap switch 30 is provided with stationary contacts 31 and 82 and with a movable contact 33. The

Serial No. 147,600.

movable contact 33 is operated through a rod 34 and lover by a pressure bellows 36 which is connected by pipe 37 with the tank 25.

The refrigerating system comprises a compressor 40 opcratively connected with an evaporator 41 and a condenser 42. Refrigerant is withdrawn from the evaporator 41 through pipe 43, and the compressed refrigerant is delivered to the condenser 42 The source of current herein shown comprises a generator which is driven by an internal-combustion engine 61. The generator and internail-combustion engine comprises a power plant which is of the automatic type, namely, one which is rendered operative automatically when there is a demand for current in a work circuit. For the purpose of this invention it is sutlicient to state that the mechanism contained withing the box (33 automatically connects a storage battery 6-1 with the generator (30 for causing said generator to operate as a motor for cranking the enginewhcn there is a demand for current within the work circuit. And, after the internal-combustion engine 61 is rendered self-operative itv will drive the generator and supply current to wires (56 and (37. The wire (36 is connected with the movable contact 83 of the snap switch 80 and the wire 67 is connected with the stationary contact 49 of switch in. The circuit for the motor of the refrigerating system comprises conductors (36, contacts 3; and 32, conductor 68, motor 47, conductor 69, contacts 50 and 4E), and conductors 70 and 67. The circuit for the motor 21 of the water system includes conductor 66, contacts and 31-, conductor 23, motor 21 and conductors 22 and 67.

When the pressure within the evaporator 41 and pipes 43 attains a certain value which is computed relative to the temperatures desired in the evaporator, the bellows 53 will expand to cause contact 50 to engage contact 49, whereby the circuit is completed between the power plant and the motor 47 and, after the power plant is self-operative, current will flow therefrom to the motor 47, whereby the motor drives the compressor #10. lVhen the pressure within the evaporators 41 and 43 attains a certain low value, the bellows 53 will operate to separate contact 50 from contact 49. Vhen the pressure with in the storage tank 25 of the water system attains a certain low value, the bellows 36 will collapse to cause contact 33 to engage contact 31 to connect the motor 21 with the power plant and after the power plant is self-operative, current from the generator 60 will energize motor 21, whereby water will be forced into the storage tank 25. It will be noted that the demand for current by the refrigerating system is subordinate to the demand for current in the water system. Although the power plant may be supplying current to the refrigerating system, a demand by the water system will cause contact 33 to separate from contact 32 to interrupt the circuit for the motor st? of the refrigerating system and connect the motor 21 of the water system with the power plant.

The current-consuming systems herein shown are merely illustrative and it is to be understood that other types of currentconsuming systems or devices may be substituted. Likewise, the generator 60 and engine 61 are herein shown merely for illustrative purposes and any source of current in which the output thereof limited.

From the foregoing description it is apparent that a svstem of electrical control has been provided for supplying the demands of a plurality of work circuits by a limited source of supply. In the present control system, such devices, in which the flow of current may be delayed temporarily are connected in a work circuit which is subordinate to a work circuit in which current must be supplied substantially as soon as there is demand therefor. Current for the device in the superior work circuit is assured substantially immediately, although current is being supplied to a device in the subordinate circuit. \Vhen there is a demand for current by a device in the su erior work circuit, the device in the subordinate work circuit is disconnected from the source of supply and the current from the source is delivered to the superior circuit. During the interval when there is no demand for current in the superior circuit, current will be available for devices'in the subordinate circuit.

\Vhile the form of embodiment of the invent-ion as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

Vhat is claimed is as follows:

1. An electrical system comprising a source of supply; a prior demand work circuit energized by said source of supply; a subordinate work circuit energized by said source of supply; a switch responsive to a demand for energy by a work apparatus in the prior demand work circuit; said subordinate circuit including contacts, one of which is directly actuated by said switch when there is a demand for energy by said work apparatus for closing said prior demand work circuit and for directly rendering said subordinate circuit inoperative; and said switch being responsive to the cessation of said demand for directly closing said subordinate circuit and for rendering said prior demand circuit inoperative.

2. An electrical system comprising a source of supply; a prior demand work circuit energized b said source of supply; a subordinate work circuit energized by said source of supply; a switch responsive to a demand for energy by a work apparatus in the prior demand work circuit; said subordinate circuit including contacts, one of which is directly actuated by said switch when there is a demand for energy by said work apparatus for closing said prior demand work circuit and for directly rendering said subordinate circuit inoperative; said switch being responsive to the cessation of said demand for directly closing said subordinate circuit and for rendering said prior demand circuit inoperative; and a second switch for rendering said subordinate circuit inoperative.

In testimony whereof I hereto aifix my signature.

LESTER S. KEILHOLTZ. 

